Can't help you here. I had two crape myrtles that were the centerpiece of my bed in the front of the house die over the winter. One sent up 3 suckers from the base, the other is completely dead. Like a dummy, I planted two dynamite crape myrtles in their place at the wife's insistence. Were they healthy when they entered dormancy? Mine got powdery mildew pretty bad just before leaf drop and we know what happened to those. I know we have been in a drought for a year and I believe you also have been? Crape myrtles are hardy in our zone, though. My parents live about 30 minutes from my place and they have literally dozens of them. Some trimmed up every year, and others left to grow naturally. They have never lost a single one in about 15 years.

Many of our Crape Myrtle cuttings drop their leaves before they show any new growth; not a problem.

If you can keep them watered, I'd go ahead and plant them where you want them now. Be forewarned that this is not the best time to be barerooting and transplanting any shrub or tree, but crape myrtles are pretty tough. They're very easy to root from cuttings. I'd probably cut at least one(if not all) of the 4 ft whips you've got into 8-inch sections, dip the basal end in rooting hormone and stick them in a pot of soilless potting mix, then keep them well-watered and sink the pot in the ground before the ground freezes this fall, and mulch well. If, however, none survive, just take some dormant cuttings from your parents' plant next march, keep 'em in a ziploc bag,wrapped in damp paper toweling, in the fridge, until next spring, then try your hand at rooting them then.

Crapes root easily a few ways. Semi-hardwood shoots taken in summer root easily in sand or perlite, sealed in a clear bag in shade. Last year's growth planted in sand or sandy loam ground in April with tips flush with the surface will root and grow. Crapes will also root sucker if the root system is damaged. They'll grow from seed, but flowers may vary. I have over 25 varieties and all are easy to propagate.